diff --git a/.circleci/config.yml b/.circleci/config.yml
index fec66bd..8700c29 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -63,13 +63,6 @@ jobs:
       - checkout
       - setup_npm
       - run: npm run lint
-      - run:
-          # NOTE: Karma loads ts-node automatically and treats karma.conf.js as a TypeScript.
-          # Karma does not starts by karma.conf.js transpile failure, and this hack removes
-          # ts-node module from the local before test.
-          # See: https://github.com/karma-runner/karma/issues/3329
-          name: Remove node-ts from node_modules
-          command: mv node_modules/ts-node node_modules/ts-node.orig
       - run: npm test
       - run: npm run package
 
diff --git a/package-lock.json b/package-lock.json
index 4300fd2..b844719 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -581,9 +581,9 @@
       "dev": true
     },
     "ajv": {
-      "version": "6.10.0",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.0.tgz",
-      "integrity": "sha512-nffhOpkymDECQyR0mnsUtoCE8RlX38G0rYP+wgLWFyZuUyuuojSSvi/+euOiQBIn63whYwYVIIH1TvE3tu4OEg==",
+      "version": "6.10.2",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.10.2.tgz",
+      "integrity": "sha512-TXtUUEYHuaTEbLZWIKUr5pmBuhDLy+8KYtPYdcV8qC+pOZL+NKqYwvWSRrVXHn+ZmRRAu8vJTAznH7Oag6RVRw==",
       "dev": true,
       "requires": {
         "fast-deep-equal": "^2.0.1",
@@ -592,6 +592,28 @@
         "uri-js": "^4.2.2"
       }
     },
+    "ajv-cli": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/ajv-cli/-/ajv-cli-3.0.0.tgz",
+      "integrity": "sha1-WCMjH2TigzBUEwaQsYCZYJ6YDyk=",
+      "dev": true,
+      "requires": {
+        "ajv": "^6.0.0",
+        "ajv-pack": "^0.3.0",
+        "fast-json-patch": "^0.5.6",
+        "glob": "^7.0.3",
+        "json-schema-migrate": "^0.2.0",
+        "minimist": "^1.2.0"
+      },
+      "dependencies": {
+        "minimist": {
+          "version": "1.2.0",
+          "resolved": "https://registry.npmjs.org/minimist/-/minimist-1.2.0.tgz",
+          "integrity": "sha1-o1AIsg9BOD7sH7kU9M1d95omQoQ=",
+          "dev": true
+        }
+      }
+    },
     "ajv-errors": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/ajv-errors/-/ajv-errors-1.0.1.tgz",
@@ -604,6 +626,16 @@
       "integrity": "sha1-6GuBnGAs+IIa1jdBNpjx3sAhhHo=",
       "dev": true
     },
+    "ajv-pack": {
+      "version": "0.3.1",
+      "resolved": "https://registry.npmjs.org/ajv-pack/-/ajv-pack-0.3.1.tgz",
+      "integrity": "sha1-tyxNQhnjko5ihC10Le2Tv1B5ZWA=",
+      "dev": true,
+      "requires": {
+        "js-beautify": "^1.6.4",
+        "require-from-string": "^1.2.0"
+      }
+    },
     "amdefine": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/amdefine/-/amdefine-1.0.1.tgz",
@@ -1576,6 +1608,12 @@
         }
       }
     },
+    "co": {
+      "version": "4.6.0",
+      "resolved": "https://registry.npmjs.org/co/-/co-4.6.0.tgz",
+      "integrity": "sha1-bqa989hTrlTMuOR7+gvz+QMfsYQ=",
+      "dev": true
+    },
     "code-point-at": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/code-point-at/-/code-point-at-1.1.0.tgz",
@@ -1670,6 +1708,16 @@
         "typedarray": "^0.0.6"
       }
     },
+    "config-chain": {
+      "version": "1.1.12",
+      "resolved": "https://registry.npmjs.org/config-chain/-/config-chain-1.1.12.tgz",
+      "integrity": "sha512-a1eOIcu8+7lUInge4Rpf/n4Krkf3Dd9lqhljRzII1/Zno/kRtUWnznPO3jOKBmTEktkt3fkxisUcivoj0ebzoA==",
+      "dev": true,
+      "requires": {
+        "ini": "^1.3.4",
+        "proto-list": "~1.2.1"
+      }
+    },
     "connect": {
       "version": "3.7.0",
       "resolved": "https://registry.npmjs.org/connect/-/connect-3.7.0.tgz",
@@ -2226,6 +2274,36 @@
         "safe-buffer": "^5.0.1"
       }
     },
+    "editorconfig": {
+      "version": "0.15.3",
+      "resolved": "https://registry.npmjs.org/editorconfig/-/editorconfig-0.15.3.tgz",
+      "integrity": "sha512-M9wIMFx96vq0R4F+gRpY3o2exzb8hEj/n9S8unZtHSvYjibBp/iMufSzvmOcV/laG0ZtuTVGtiJggPOSW2r93g==",
+      "dev": true,
+      "requires": {
+        "commander": "^2.19.0",
+        "lru-cache": "^4.1.5",
+        "semver": "^5.6.0",
+        "sigmund": "^1.0.1"
+      },
+      "dependencies": {
+        "commander": {
+          "version": "2.20.3",
+          "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.3.tgz",
+          "integrity": "sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==",
+          "dev": true
+        },
+        "lru-cache": {
+          "version": "4.1.5",
+          "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-4.1.5.tgz",
+          "integrity": "sha512-sWZlbEP2OsHNkXrMl5GYk/jKk70MBng6UU4YI/qGDYbgf6YbP4EvmqISbXCoJiRKs+1bSpFHVgQxvJ17F2li5g==",
+          "dev": true,
+          "requires": {
+            "pseudomap": "^1.0.2",
+            "yallist": "^2.1.2"
+          }
+        }
+      }
+    },
     "ee-first": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
@@ -3077,6 +3155,12 @@
       "integrity": "sha1-ewUhjd+WZ79/Nwv3/bLLFf3Qqkk=",
       "dev": true
     },
+    "fast-json-patch": {
+      "version": "0.5.7",
+      "resolved": "https://registry.npmjs.org/fast-json-patch/-/fast-json-patch-0.5.7.tgz",
+      "integrity": "sha1-taj0nSWWJFlu+YuHLz/aiVtNhmU=",
+      "dev": true
+    },
     "fast-json-stable-stringify": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz",
@@ -4946,6 +5030,45 @@
       "integrity": "sha512-M7kLczedRMYX4L8Mdh4MzyAMM9O5osx+4FcOQuTvr3A9F2D9S5JXheN0ewNbrvK2UatkTRhL5ejGmGSjNMiZuw==",
       "dev": true
     },
+    "js-beautify": {
+      "version": "1.10.2",
+      "resolved": "https://registry.npmjs.org/js-beautify/-/js-beautify-1.10.2.tgz",
+      "integrity": "sha512-ZtBYyNUYJIsBWERnQP0rPN9KjkrDfJcMjuVGcvXOUJrD1zmOGwhRwQ4msG+HJ+Ni/FA7+sRQEMYVzdTQDvnzvQ==",
+      "dev": true,
+      "requires": {
+        "config-chain": "^1.1.12",
+        "editorconfig": "^0.15.3",
+        "glob": "^7.1.3",
+        "mkdirp": "~0.5.1",
+        "nopt": "~4.0.1"
+      },
+      "dependencies": {
+        "glob": {
+          "version": "7.1.6",
+          "resolved": "https://registry.npmjs.org/glob/-/glob-7.1.6.tgz",
+          "integrity": "sha512-LwaxwyZ72Lk7vZINtNNrywX0ZuLyStrdDtabefZKAY5ZGJhVtgdznluResxNmPitE0SAO+O26sWTHeKSI2wMBA==",
+          "dev": true,
+          "requires": {
+            "fs.realpath": "^1.0.0",
+            "inflight": "^1.0.4",
+            "inherits": "2",
+            "minimatch": "^3.0.4",
+            "once": "^1.3.0",
+            "path-is-absolute": "^1.0.0"
+          }
+        },
+        "nopt": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/nopt/-/nopt-4.0.1.tgz",
+          "integrity": "sha1-0NRoWv1UFRk8jHUFYC0NF81kR00=",
+          "dev": true,
+          "requires": {
+            "abbrev": "1",
+            "osenv": "^0.1.4"
+          }
+        }
+      }
+    },
     "js-tokens": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/js-tokens/-/js-tokens-3.0.2.tgz",
@@ -4980,6 +5103,41 @@
       "integrity": "sha1-tIDIkuWaLwWVTOcnvT8qTogvnhM=",
       "dev": true
     },
+    "json-schema-migrate": {
+      "version": "0.2.0",
+      "resolved": "https://registry.npmjs.org/json-schema-migrate/-/json-schema-migrate-0.2.0.tgz",
+      "integrity": "sha1-ukelsAcvxyOWRg4b1gtE1SF4u8Y=",
+      "dev": true,
+      "requires": {
+        "ajv": "^5.0.0"
+      },
+      "dependencies": {
+        "ajv": {
+          "version": "5.5.2",
+          "resolved": "https://registry.npmjs.org/ajv/-/ajv-5.5.2.tgz",
+          "integrity": "sha1-c7Xuyj+rZT49P5Qis0GtQiBdyWU=",
+          "dev": true,
+          "requires": {
+            "co": "^4.6.0",
+            "fast-deep-equal": "^1.0.0",
+            "fast-json-stable-stringify": "^2.0.0",
+            "json-schema-traverse": "^0.3.0"
+          }
+        },
+        "fast-deep-equal": {
+          "version": "1.1.0",
+          "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-1.1.0.tgz",
+          "integrity": "sha1-wFNHeBfIa1HaqFPIHgWbcz0CNhQ=",
+          "dev": true
+        },
+        "json-schema-traverse": {
+          "version": "0.3.1",
+          "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.3.1.tgz",
+          "integrity": "sha1-NJptRMU6Ud6JtAgFxdXlm0F9M0A=",
+          "dev": true
+        }
+      }
+    },
     "json-schema-traverse": {
       "version": "0.4.1",
       "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz",
@@ -7357,6 +7515,12 @@
         }
       }
     },
+    "proto-list": {
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/proto-list/-/proto-list-1.2.4.tgz",
+      "integrity": "sha1-IS1b/hMYMGpCD2QCuOJv85ZHqEk=",
+      "dev": true
+    },
     "proxy-addr": {
       "version": "2.0.5",
       "resolved": "https://registry.npmjs.org/proxy-addr/-/proxy-addr-2.0.5.tgz",
@@ -7884,6 +8048,12 @@
       "integrity": "sha1-jGStX9MNqxyXbiNE/+f3kqam30I=",
       "dev": true
     },
+    "require-from-string": {
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-1.2.1.tgz",
+      "integrity": "sha1-UpyczvJzgK3+yaL5ZbZJu+5jZBg=",
+      "dev": true
+    },
     "require-main-filename": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/require-main-filename/-/require-main-filename-1.0.1.tgz",
@@ -8339,6 +8509,12 @@
       "integrity": "sha1-2kL0l0DAtC2yypcoVxyxkMmO/qM=",
       "dev": true
     },
+    "sigmund": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/sigmund/-/sigmund-1.0.1.tgz",
+      "integrity": "sha1-P/IfGYytIXX587eBhT/ZTQ0ZtZA=",
+      "dev": true
+    },
     "signal-exit": {
       "version": "3.0.2",
       "resolved": "https://registry.npmjs.org/signal-exit/-/signal-exit-3.0.2.tgz",
diff --git a/package.json b/package.json
index 726e909..381bb7d 100644
--- a/package.json
+++ b/package.json
@@ -2,10 +2,11 @@
   "name": "vim-vixen",
   "description": "Vim vixen",
   "scripts": {
+    "schema": "ajv compile -s src/shared/settings/schema.json -o src/shared/settings/validate.js",
     "start": "webpack --mode development -w --debug --devtool inline-source-map",
     "build": "NODE_ENV=production webpack --mode production --progress --display-error-details --devtool inline-source-map",
     "package": "npm run build && script/package",
-    "lint": "eslint --ext .js,.jsx,.ts,.tsx src",
+    "lint": "eslint --ext .ts,.tsx src",
     "type-checks": "tsc --noEmit",
     "test": "karma start",
     "test:e2e": "mocha --timeout 10000 --retries 10 --require ts-node/register --extension ts e2e"
@@ -35,6 +36,8 @@
     "@types/sinon": "^7.0.13",
     "@typescript-eslint/eslint-plugin": "^2.0.0",
     "@typescript-eslint/parser": "^2.0.0",
+    "ajv": "^6.10.2",
+    "ajv-cli": "^3.0.0",
     "chai": "^4.2.0",
     "css-loader": "^3.2.0",
     "eslint": "^6.2.2",
diff --git a/src/shared/settings/Blacklist.ts b/src/shared/settings/Blacklist.ts
index 0cfbd71..1903a78 100644
--- a/src/shared/settings/Blacklist.ts
+++ b/src/shared/settings/Blacklist.ts
@@ -12,18 +12,6 @@ const regexFromWildcard = (pattern: string): RegExp => {
   return new RegExp(regexStr);
 };
 
-const isArrayOfString = (raw: any): boolean => {
-  if (!Array.isArray(raw)) {
-    return false;
-  }
-  for (let x of Array.from(raw)) {
-    if (typeof x !== 'string') {
-      return false;
-    }
-  }
-  return true;
-};
-
 export class BlacklistItem {
   public readonly pattern: string;
 
@@ -47,30 +35,10 @@ export class BlacklistItem {
     this.keyEntities = this.keys.map(Key.fromMapKey);
   }
 
-  static fromJSON(raw: any): BlacklistItem {
-    if (typeof raw === 'string') {
-      return new BlacklistItem(raw, false, []);
-    } else if (typeof raw === 'object' && raw !== null) {
-      if (!('url' in raw)) {
-        throw new TypeError(
-          `missing field "url" of blacklist item: ${JSON.stringify(raw)}`);
-      }
-      if (typeof raw.url !== 'string') {
-        throw new TypeError(
-          `invalid field "url" of blacklist item: ${JSON.stringify(raw)}`);
-      }
-      if (!('keys' in raw)) {
-        throw new TypeError(
-          `missing field "keys" of blacklist item: ${JSON.stringify(raw)}`);
-      }
-      if (!isArrayOfString(raw.keys)) {
-        throw new TypeError(
-          `invalid field "keys" of blacklist item: ${JSON.stringify(raw)}`);
-      }
-      return new BlacklistItem(raw.url as string, true, raw.keys as string[]);
-    }
-    throw new TypeError(
-      `invalid format of blacklist item: ${JSON.stringify(raw)}`);
+  static fromJSON(json: BlacklistItemJSON): BlacklistItem {
+    return typeof json === 'string'
+      ? new BlacklistItem(json, false, [])
+      : new BlacklistItem(json.url, true, json.keys);
   }
 
   toJSON(): BlacklistItemJSON {
@@ -103,11 +71,8 @@ export default class Blacklist {
   ) {
   }
 
-  static fromJSON(json: any): Blacklist {
-    if (!Array.isArray(json)) {
-      throw new TypeError('blacklist is not an array: ' + JSON.stringify(json));
-    }
-    let items = Array.from(json).map(item => BlacklistItem.fromJSON(item));
+  static fromJSON(json: BlacklistJSON): Blacklist {
+    let items = json.map(o => BlacklistItem.fromJSON(o));
     return new Blacklist(items);
   }
 
diff --git a/src/shared/settings/Keymaps.ts b/src/shared/settings/Keymaps.ts
index a5558b0..5870313 100644
--- a/src/shared/settings/Keymaps.ts
+++ b/src/shared/settings/Keymaps.ts
@@ -1,23 +1,25 @@
 import * as operations from '../operations';
 
-export type KeymapsJSON = { [key: string]: operations.Operation };
+type OperationJson = {
+  type: string
+} | {
+  type: string;
+  [prop: string]: string | number | boolean;
+};
+export type KeymapsJSON = { [key: string]: OperationJson };
 
 export default class Keymaps {
   constructor(
-    private readonly data: KeymapsJSON,
+    private readonly data: { [key: string]: operations.Operation },
   ) {
   }
 
-  static fromJSON(json: any): Keymaps {
-    if (typeof json !== 'object' || json === null) {
-      throw new TypeError('invalid keymaps type: ' + JSON.stringify(json));
-    }
-
-    let data: KeymapsJSON = {};
+  static fromJSON(json: KeymapsJSON): Keymaps {
+    let entries: { [key: string]: operations.Operation } = {};
     for (let key of Object.keys(json)) {
-      data[key] = operations.valueOf(json[key]);
+      entries[key] = operations.valueOf(json[key]);
     }
-    return new Keymaps(data);
+    return new Keymaps(entries);
   }
 
   combine(other: Keymaps): Keymaps {
diff --git a/src/shared/settings/Properties.ts b/src/shared/settings/Properties.ts
index 63ff991..27fb62e 100644
--- a/src/shared/settings/Properties.ts
+++ b/src/shared/settings/Properties.ts
@@ -1,3 +1,4 @@
+
 export type PropertiesJSON = {
   hintchars?: string;
   smoothscroll?: boolean;
@@ -65,22 +66,7 @@ export default class Properties {
     this.complete = complete || defaultValues.complete;
   }
 
-  static fromJSON(json: any): Properties {
-    let defNames: Set<string> = new Set(defs.map(def => def.name));
-    let unknownName = Object.keys(json).find(name => !defNames.has(name));
-    if (unknownName) {
-      throw new TypeError(`Unknown property name: "${unknownName}"`);
-    }
-
-    for (let def of defs) {
-      if (!Object.prototype.hasOwnProperty.call(json, def.name)) {
-        continue;
-      }
-      if (typeof json[def.name] !== def.type) {
-        throw new TypeError(
-          `property "${def.name}" is not ${def.type}`);
-      }
-    }
+  static fromJSON(json: PropertiesJSON): Properties {
     return new Properties(json);
   }
 
diff --git a/src/shared/settings/Search.ts b/src/shared/settings/Search.ts
index 4580236..7d7e555 100644
--- a/src/shared/settings/Search.ts
+++ b/src/shared/settings/Search.ts
@@ -12,18 +12,10 @@ export default class Search {
   ) {
   }
 
-  static fromJSON(json: any): Search {
-    let defaultEngine = Search.getStringField(json, 'default');
-    let engines = Search.getObjectField(json, 'engines');
-
-    for (let [name, url] of Object.entries(engines)) {
-      if ((/\s/).test(name)) {
-        throw new TypeError(
-          `While space in the search engine not allowed: "${name}"`);
-      }
-      if (typeof url !== 'string') {
-        throw new TypeError(
-          `Invalid type of value in filed "engines": ${JSON.stringify(json)}`);
+  static fromJSON(json: SearchJSON): Search {
+    for (let [name, url] of Object.entries(json.engines)) {
+      if (!(/^[a-zA-Z0-9]+$/).test(name)) {
+        throw new TypeError('Search engine\'s name must be [a-zA-Z0-9]+');
       }
       let matches = url.match(/{}/g);
       if (matches === null) {
@@ -32,15 +24,11 @@ export default class Search {
         throw new TypeError(`Multiple {}-placeholders in URL of "${name}"`);
       }
     }
-
-    if (!Object.keys(engines).includes(defaultEngine)) {
-      throw new TypeError(`Default engine "${defaultEngine}" not found`);
+    if (!Object.keys(json.engines).includes(json.default)) {
+      throw new TypeError(`Default engine "${json.default}" not found`);
     }
 
-    return new Search(
-      json.default as string,
-      json.engines,
-    );
+    return new Search(json.default, json.engines);
   }
 
   toJSON(): SearchJSON {
@@ -49,28 +37,4 @@ export default class Search {
       engines: this.engines,
     };
   }
-
-  private static getStringField(json: any, name: string): string {
-    if (!Object.prototype.hasOwnProperty.call(json, name)) {
-      throw new TypeError(
-        `missing field "${name}" on search: ${JSON.stringify(json)}`);
-    }
-    if (typeof json[name] !== 'string') {
-      throw new TypeError(
-        `invalid type of filed "${name}" on search: ${JSON.stringify(json)}`);
-    }
-    return json[name];
-  }
-
-  private static getObjectField(json: any, name: string): Object {
-    if (!Object.prototype.hasOwnProperty.call(json, name)) {
-      throw new TypeError(
-        `missing field "${name}" on search: ${JSON.stringify(json)}`);
-    }
-    if (typeof json[name] !== 'object' || json[name] === null) {
-      throw new TypeError(
-        `invalid type of filed "${name}" on search: ${JSON.stringify(json)}`);
-    }
-    return json[name];
-  }
 }
diff --git a/src/shared/settings/Settings.ts b/src/shared/settings/Settings.ts
index 2c9e37f..97dda7f 100644
--- a/src/shared/settings/Settings.ts
+++ b/src/shared/settings/Settings.ts
@@ -1,13 +1,16 @@
+import Ajv from 'ajv';
+
 import Keymaps, { KeymapsJSON } from './Keymaps';
 import Search, { SearchJSON } from './Search';
 import Properties, { PropertiesJSON } from './Properties';
 import Blacklist, { BlacklistJSON } from './Blacklist';
+import validate from './validate';
 
 export type SettingsJSON = {
-  keymaps: KeymapsJSON,
-  search: SearchJSON,
-  properties: PropertiesJSON,
-  blacklist: BlacklistJSON,
+  keymaps?: KeymapsJSON,
+  search?: SearchJSON,
+  properties?: PropertiesJSON,
+  blacklist?: BlacklistJSON,
 };
 
 export default class Settings {
@@ -36,25 +39,30 @@ export default class Settings {
     this.blacklist = blacklist;
   }
 
-  static fromJSON(json: any): Settings {
+  static fromJSON(json: unknown): Settings {
+    let valid = validate(json);
+    if (!valid) {
+      let message = (validate as any).errors!!
+        .map((err: Ajv.ErrorObject) => {
+          return `'${err.dataPath}' ${err.message}`;
+        })
+        .join('; ');
+      throw new TypeError(message);
+    }
+
+    let obj = json as SettingsJSON;
     let settings = { ...DefaultSetting };
-    for (let key of Object.keys(json)) {
-      switch (key) {
-      case 'keymaps':
-        settings.keymaps = Keymaps.fromJSON(json.keymaps);
-        break;
-      case 'search':
-        settings.search = Search.fromJSON(json.search);
-        break;
-      case 'properties':
-        settings.properties = Properties.fromJSON(json.properties);
-        break;
-      case 'blacklist':
-        settings.blacklist = Blacklist.fromJSON(json.blacklist);
-        break;
-      default:
-        throw new TypeError('unknown setting: ' + key);
-      }
+    if (obj.keymaps) {
+      settings.keymaps = Keymaps.fromJSON(obj.keymaps);
+    }
+    if (obj.search) {
+      settings.search = Search.fromJSON(obj.search);
+    }
+    if (obj.properties) {
+      settings.properties = Properties.fromJSON(obj.properties);
+    }
+    if (obj.blacklist) {
+      settings.blacklist = Blacklist.fromJSON(obj.blacklist);
     }
     return new Settings(settings);
   }
diff --git a/src/shared/settings/schema.json b/src/shared/settings/schema.json
new file mode 100644
index 0000000..31d47f1
--- /dev/null
+++ b/src/shared/settings/schema.json
@@ -0,0 +1,84 @@
+{
+  "type": "object",
+  "properties": {
+    "keymaps": {
+      "type": "object",
+      "patternProperties": {
+        ".*": {
+          "type": "object",
+          "properties": {
+            "type": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "type"
+          ]
+        }
+      }
+    },
+    "search": {
+      "type": "object",
+      "properties": {
+        "default": {
+          "type": "string"
+        },
+        "engines": {
+          "type": "object",
+          "patternProperties": {
+            ".*": {
+              "type": "string"
+            }
+          }
+        }
+      },
+      "required": [
+        "default",
+        "engines"
+      ]
+    },
+    "properties": {
+      "type": "object",
+      "properties": {
+        "hintchars": {
+          "type": "string"
+        },
+        "smoothscroll": {
+          "type": "boolean"
+        },
+        "complete": {
+          "type": "string"
+        }
+      }
+    },
+    "blacklist": {
+      "type": "array",
+      "items": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "object",
+            "properties": {
+              "url": {
+                "type": "string"
+              },
+              "keys": {
+                "type": "array",
+                "items": {
+                  "type": "string"
+                }
+              }
+            },
+            "required": [
+              "url",
+              "keys"
+            ]
+          }
+        ]
+      }
+    }
+  },
+  "additionalProperties": false
+}
diff --git a/src/shared/settings/validate.js b/src/shared/settings/validate.js
new file mode 100644
index 0000000..236488d
--- /dev/null
+++ b/src/shared/settings/validate.js
@@ -0,0 +1,567 @@
+'use strict';
+var validate = (function() {
+  var pattern0 = new RegExp('.*');
+  var refVal = [];
+  return function validate(data, dataPath, parentData, parentDataProperty, rootData) {
+    'use strict';
+    var vErrors = null;
+    var errors = 0;
+    if ((data && typeof data === "object" && !Array.isArray(data))) {
+      var errs__0 = errors;
+      var valid1 = true;
+      for (var key0 in data) {
+        var isAdditional0 = !(false || key0 == 'keymaps' || key0 == 'search' || key0 == 'properties' || key0 == 'blacklist');
+        if (isAdditional0) {
+          valid1 = false;
+          validate.errors = [{
+            keyword: 'additionalProperties',
+            dataPath: (dataPath || '') + "",
+            schemaPath: '#/additionalProperties',
+            params: {
+              additionalProperty: '' + key0 + ''
+            },
+            message: 'should NOT have additional properties'
+          }];
+          return false;
+          break;
+        }
+      }
+      if (valid1) {
+        var data1 = data.keymaps;
+        if (data1 === undefined) {
+          valid1 = true;
+        } else {
+          var errs_1 = errors;
+          if ((data1 && typeof data1 === "object" && !Array.isArray(data1))) {
+            var errs__1 = errors;
+            var valid2 = true;
+            for (var key1 in data1) {
+              if (pattern0.test(key1)) {
+                var data2 = data1[key1];
+                var errs_2 = errors;
+                if ((data2 && typeof data2 === "object" && !Array.isArray(data2))) {
+                  if (true) {
+                    var errs__2 = errors;
+                    var valid3 = true;
+                    if (data2.type === undefined) {
+                      valid3 = false;
+                      validate.errors = [{
+                        keyword: 'required',
+                        dataPath: (dataPath || '') + '.keymaps[\'' + key1 + '\']',
+                        schemaPath: '#/properties/keymaps/patternProperties/.*/required',
+                        params: {
+                          missingProperty: 'type'
+                        },
+                        message: 'should have required property \'type\''
+                      }];
+                      return false;
+                    } else {
+                      var errs_3 = errors;
+                      if (typeof data2.type !== "string") {
+                        validate.errors = [{
+                          keyword: 'type',
+                          dataPath: (dataPath || '') + '.keymaps[\'' + key1 + '\'].type',
+                          schemaPath: '#/properties/keymaps/patternProperties/.*/properties/type/type',
+                          params: {
+                            type: 'string'
+                          },
+                          message: 'should be string'
+                        }];
+                        return false;
+                      }
+                      var valid3 = errors === errs_3;
+                    }
+                  }
+                } else {
+                  validate.errors = [{
+                    keyword: 'type',
+                    dataPath: (dataPath || '') + '.keymaps[\'' + key1 + '\']',
+                    schemaPath: '#/properties/keymaps/patternProperties/.*/type',
+                    params: {
+                      type: 'object'
+                    },
+                    message: 'should be object'
+                  }];
+                  return false;
+                }
+                var valid2 = errors === errs_2;
+                if (!valid2) break;
+              } else valid2 = true;
+            }
+          } else {
+            validate.errors = [{
+              keyword: 'type',
+              dataPath: (dataPath || '') + '.keymaps',
+              schemaPath: '#/properties/keymaps/type',
+              params: {
+                type: 'object'
+              },
+              message: 'should be object'
+            }];
+            return false;
+          }
+          var valid1 = errors === errs_1;
+        }
+        if (valid1) {
+          var data1 = data.search;
+          if (data1 === undefined) {
+            valid1 = true;
+          } else {
+            var errs_1 = errors;
+            if ((data1 && typeof data1 === "object" && !Array.isArray(data1))) {
+              if (true) {
+                var errs__1 = errors;
+                var valid2 = true;
+                if (data1.default === undefined) {
+                  valid2 = false;
+                  validate.errors = [{
+                    keyword: 'required',
+                    dataPath: (dataPath || '') + '.search',
+                    schemaPath: '#/properties/search/required',
+                    params: {
+                      missingProperty: 'default'
+                    },
+                    message: 'should have required property \'default\''
+                  }];
+                  return false;
+                } else {
+                  var errs_2 = errors;
+                  if (typeof data1.default !== "string") {
+                    validate.errors = [{
+                      keyword: 'type',
+                      dataPath: (dataPath || '') + '.search.default',
+                      schemaPath: '#/properties/search/properties/default/type',
+                      params: {
+                        type: 'string'
+                      },
+                      message: 'should be string'
+                    }];
+                    return false;
+                  }
+                  var valid2 = errors === errs_2;
+                }
+                if (valid2) {
+                  var data2 = data1.engines;
+                  if (data2 === undefined) {
+                    valid2 = false;
+                    validate.errors = [{
+                      keyword: 'required',
+                      dataPath: (dataPath || '') + '.search',
+                      schemaPath: '#/properties/search/required',
+                      params: {
+                        missingProperty: 'engines'
+                      },
+                      message: 'should have required property \'engines\''
+                    }];
+                    return false;
+                  } else {
+                    var errs_2 = errors;
+                    if ((data2 && typeof data2 === "object" && !Array.isArray(data2))) {
+                      var errs__2 = errors;
+                      var valid3 = true;
+                      for (var key2 in data2) {
+                        if (pattern0.test(key2)) {
+                          var errs_3 = errors;
+                          if (typeof data2[key2] !== "string") {
+                            validate.errors = [{
+                              keyword: 'type',
+                              dataPath: (dataPath || '') + '.search.engines[\'' + key2 + '\']',
+                              schemaPath: '#/properties/search/properties/engines/patternProperties/.*/type',
+                              params: {
+                                type: 'string'
+                              },
+                              message: 'should be string'
+                            }];
+                            return false;
+                          }
+                          var valid3 = errors === errs_3;
+                          if (!valid3) break;
+                        } else valid3 = true;
+                      }
+                    } else {
+                      validate.errors = [{
+                        keyword: 'type',
+                        dataPath: (dataPath || '') + '.search.engines',
+                        schemaPath: '#/properties/search/properties/engines/type',
+                        params: {
+                          type: 'object'
+                        },
+                        message: 'should be object'
+                      }];
+                      return false;
+                    }
+                    var valid2 = errors === errs_2;
+                  }
+                }
+              }
+            } else {
+              validate.errors = [{
+                keyword: 'type',
+                dataPath: (dataPath || '') + '.search',
+                schemaPath: '#/properties/search/type',
+                params: {
+                  type: 'object'
+                },
+                message: 'should be object'
+              }];
+              return false;
+            }
+            var valid1 = errors === errs_1;
+          }
+          if (valid1) {
+            var data1 = data.properties;
+            if (data1 === undefined) {
+              valid1 = true;
+            } else {
+              var errs_1 = errors;
+              if ((data1 && typeof data1 === "object" && !Array.isArray(data1))) {
+                var errs__1 = errors;
+                var valid2 = true;
+                if (data1.hintchars === undefined) {
+                  valid2 = true;
+                } else {
+                  var errs_2 = errors;
+                  if (typeof data1.hintchars !== "string") {
+                    validate.errors = [{
+                      keyword: 'type',
+                      dataPath: (dataPath || '') + '.properties.hintchars',
+                      schemaPath: '#/properties/properties/properties/hintchars/type',
+                      params: {
+                        type: 'string'
+                      },
+                      message: 'should be string'
+                    }];
+                    return false;
+                  }
+                  var valid2 = errors === errs_2;
+                }
+                if (valid2) {
+                  if (data1.smoothscroll === undefined) {
+                    valid2 = true;
+                  } else {
+                    var errs_2 = errors;
+                    if (typeof data1.smoothscroll !== "boolean") {
+                      validate.errors = [{
+                        keyword: 'type',
+                        dataPath: (dataPath || '') + '.properties.smoothscroll',
+                        schemaPath: '#/properties/properties/properties/smoothscroll/type',
+                        params: {
+                          type: 'boolean'
+                        },
+                        message: 'should be boolean'
+                      }];
+                      return false;
+                    }
+                    var valid2 = errors === errs_2;
+                  }
+                  if (valid2) {
+                    if (data1.complete === undefined) {
+                      valid2 = true;
+                    } else {
+                      var errs_2 = errors;
+                      if (typeof data1.complete !== "string") {
+                        validate.errors = [{
+                          keyword: 'type',
+                          dataPath: (dataPath || '') + '.properties.complete',
+                          schemaPath: '#/properties/properties/properties/complete/type',
+                          params: {
+                            type: 'string'
+                          },
+                          message: 'should be string'
+                        }];
+                        return false;
+                      }
+                      var valid2 = errors === errs_2;
+                    }
+                  }
+                }
+              } else {
+                validate.errors = [{
+                  keyword: 'type',
+                  dataPath: (dataPath || '') + '.properties',
+                  schemaPath: '#/properties/properties/type',
+                  params: {
+                    type: 'object'
+                  },
+                  message: 'should be object'
+                }];
+                return false;
+              }
+              var valid1 = errors === errs_1;
+            }
+            if (valid1) {
+              var data1 = data.blacklist;
+              if (data1 === undefined) {
+                valid1 = true;
+              } else {
+                var errs_1 = errors;
+                if (Array.isArray(data1)) {
+                  var errs__1 = errors;
+                  var valid1;
+                  for (var i1 = 0; i1 < data1.length; i1++) {
+                    var data2 = data1[i1];
+                    var errs_2 = errors;
+                    var errs__2 = errors;
+                    var valid2 = false;
+                    var errs_3 = errors;
+                    if (typeof data2 !== "string") {
+                      var err = {
+                        keyword: 'type',
+                        dataPath: (dataPath || '') + '.blacklist[' + i1 + ']',
+                        schemaPath: '#/properties/blacklist/items/anyOf/0/type',
+                        params: {
+                          type: 'string'
+                        },
+                        message: 'should be string'
+                      };
+                      if (vErrors === null) vErrors = [err];
+                      else vErrors.push(err);
+                      errors++;
+                    }
+                    var valid3 = errors === errs_3;
+                    valid2 = valid2 || valid3;
+                    if (!valid2) {
+                      var errs_3 = errors;
+                      if ((data2 && typeof data2 === "object" && !Array.isArray(data2))) {
+                        if (true) {
+                          var errs__3 = errors;
+                          var valid4 = true;
+                          if (data2.url === undefined) {
+                            valid4 = false;
+                            var err = {
+                              keyword: 'required',
+                              dataPath: (dataPath || '') + '.blacklist[' + i1 + ']',
+                              schemaPath: '#/properties/blacklist/items/anyOf/1/required',
+                              params: {
+                                missingProperty: 'url'
+                              },
+                              message: 'should have required property \'url\''
+                            };
+                            if (vErrors === null) vErrors = [err];
+                            else vErrors.push(err);
+                            errors++;
+                          } else {
+                            var errs_4 = errors;
+                            if (typeof data2.url !== "string") {
+                              var err = {
+                                keyword: 'type',
+                                dataPath: (dataPath || '') + '.blacklist[' + i1 + '].url',
+                                schemaPath: '#/properties/blacklist/items/anyOf/1/properties/url/type',
+                                params: {
+                                  type: 'string'
+                                },
+                                message: 'should be string'
+                              };
+                              if (vErrors === null) vErrors = [err];
+                              else vErrors.push(err);
+                              errors++;
+                            }
+                            var valid4 = errors === errs_4;
+                          }
+                          if (valid4) {
+                            var data3 = data2.keys;
+                            if (data3 === undefined) {
+                              valid4 = false;
+                              var err = {
+                                keyword: 'required',
+                                dataPath: (dataPath || '') + '.blacklist[' + i1 + ']',
+                                schemaPath: '#/properties/blacklist/items/anyOf/1/required',
+                                params: {
+                                  missingProperty: 'keys'
+                                },
+                                message: 'should have required property \'keys\''
+                              };
+                              if (vErrors === null) vErrors = [err];
+                              else vErrors.push(err);
+                              errors++;
+                            } else {
+                              var errs_4 = errors;
+                              if (Array.isArray(data3)) {
+                                var errs__4 = errors;
+                                var valid4;
+                                for (var i4 = 0; i4 < data3.length; i4++) {
+                                  var errs_5 = errors;
+                                  if (typeof data3[i4] !== "string") {
+                                    var err = {
+                                      keyword: 'type',
+                                      dataPath: (dataPath || '') + '.blacklist[' + i1 + '].keys[' + i4 + ']',
+                                      schemaPath: '#/properties/blacklist/items/anyOf/1/properties/keys/items/type',
+                                      params: {
+                                        type: 'string'
+                                      },
+                                      message: 'should be string'
+                                    };
+                                    if (vErrors === null) vErrors = [err];
+                                    else vErrors.push(err);
+                                    errors++;
+                                  }
+                                  var valid5 = errors === errs_5;
+                                  if (!valid5) break;
+                                }
+                              } else {
+                                var err = {
+                                  keyword: 'type',
+                                  dataPath: (dataPath || '') + '.blacklist[' + i1 + '].keys',
+                                  schemaPath: '#/properties/blacklist/items/anyOf/1/properties/keys/type',
+                                  params: {
+                                    type: 'array'
+                                  },
+                                  message: 'should be array'
+                                };
+                                if (vErrors === null) vErrors = [err];
+                                else vErrors.push(err);
+                                errors++;
+                              }
+                              var valid4 = errors === errs_4;
+                            }
+                          }
+                        }
+                      } else {
+                        var err = {
+                          keyword: 'type',
+                          dataPath: (dataPath || '') + '.blacklist[' + i1 + ']',
+                          schemaPath: '#/properties/blacklist/items/anyOf/1/type',
+                          params: {
+                            type: 'object'
+                          },
+                          message: 'should be object'
+                        };
+                        if (vErrors === null) vErrors = [err];
+                        else vErrors.push(err);
+                        errors++;
+                      }
+                      var valid3 = errors === errs_3;
+                      valid2 = valid2 || valid3;
+                    }
+                    if (!valid2) {
+                      var err = {
+                        keyword: 'anyOf',
+                        dataPath: (dataPath || '') + '.blacklist[' + i1 + ']',
+                        schemaPath: '#/properties/blacklist/items/anyOf',
+                        params: {},
+                        message: 'should match some schema in anyOf'
+                      };
+                      if (vErrors === null) vErrors = [err];
+                      else vErrors.push(err);
+                      errors++;
+                      validate.errors = vErrors;
+                      return false;
+                    } else {
+                      errors = errs__2;
+                      if (vErrors !== null) {
+                        if (errs__2) vErrors.length = errs__2;
+                        else vErrors = null;
+                      }
+                    }
+                    var valid2 = errors === errs_2;
+                    if (!valid2) break;
+                  }
+                } else {
+                  validate.errors = [{
+                    keyword: 'type',
+                    dataPath: (dataPath || '') + '.blacklist',
+                    schemaPath: '#/properties/blacklist/type',
+                    params: {
+                      type: 'array'
+                    },
+                    message: 'should be array'
+                  }];
+                  return false;
+                }
+                var valid1 = errors === errs_1;
+              }
+            }
+          }
+        }
+      }
+    } else {
+      validate.errors = [{
+        keyword: 'type',
+        dataPath: (dataPath || '') + "",
+        schemaPath: '#/type',
+        params: {
+          type: 'object'
+        },
+        message: 'should be object'
+      }];
+      return false;
+    }
+    validate.errors = vErrors;
+    return errors === 0;
+  };
+})();
+validate.schema = {
+  "type": "object",
+  "properties": {
+    "keymaps": {
+      "type": "object",
+      "patternProperties": {
+        ".*": {
+          "type": "object",
+          "properties": {
+            "type": {
+              "type": "string"
+            }
+          },
+          "required": ["type"]
+        }
+      }
+    },
+    "search": {
+      "type": "object",
+      "properties": {
+        "default": {
+          "type": "string"
+        },
+        "engines": {
+          "type": "object",
+          "patternProperties": {
+            ".*": {
+              "type": "string"
+            }
+          }
+        }
+      },
+      "required": ["default", "engines"]
+    },
+    "properties": {
+      "type": "object",
+      "properties": {
+        "hintchars": {
+          "type": "string"
+        },
+        "smoothscroll": {
+          "type": "boolean"
+        },
+        "complete": {
+          "type": "string"
+        }
+      }
+    },
+    "blacklist": {
+      "type": "array",
+      "items": {
+        "anyOf": [{
+          "type": "string"
+        }, {
+          "type": "object",
+          "properties": {
+            "url": {
+              "type": "string"
+            },
+            "keys": {
+              "type": "array",
+              "items": {
+                "type": "string"
+              }
+            }
+          },
+          "required": ["url", "keys"]
+        }]
+      }
+    }
+  },
+  "additionalProperties": false
+};
+validate.errors = null;
+module.exports = validate;
\ No newline at end of file
diff --git a/test/shared/settings/Blacklist.test.ts b/test/shared/settings/Blacklist.test.ts
index 133112c..0112757 100644
--- a/test/shared/settings/Blacklist.test.ts
+++ b/test/shared/settings/Blacklist.test.ts
@@ -16,16 +16,6 @@ describe('BlacklistItem', () => {
       expect(item.partial).to.be.true;
       expect(item.keys).to.deep.equal(['j', 'k']);
     });
-
-    it('throws a TypeError', () => {
-      expect(() => BlacklistItem.fromJSON(null)).to.throw(TypeError);
-      expect(() => BlacklistItem.fromJSON(100)).to.throw(TypeError);
-      expect(() => BlacklistItem.fromJSON({})).to.throw(TypeError);
-      expect(() => BlacklistItem.fromJSON({url: 'google.com'})).to.throw(TypeError);
-      expect(() => BlacklistItem.fromJSON({keys: ['a']})).to.throw(TypeError);
-      expect(() => BlacklistItem.fromJSON({url: 'google.com', keys: 10})).to.throw(TypeError);
-      expect(() => BlacklistItem.fromJSON({url: 'google.com', keys: ['a', 'b', 3]})).to.throw(TypeError);
-    });
   });
 
   describe('#matches', () => {
@@ -118,14 +108,6 @@ describe('Blacklist', () => {
       let blacklist = Blacklist.fromJSON([]);
       expect(blacklist.toJSON()).to.deep.equals([]);
     });
-
-    it('throws a TypeError', () => {
-      expect(() => Blacklist.fromJSON(null)).to.throw(TypeError);
-      expect(() => Blacklist.fromJSON(100)).to.throw(TypeError);
-      expect(() => Blacklist.fromJSON({})).to.throw(TypeError);
-      expect(() => Blacklist.fromJSON([100])).to.throw(TypeError);
-      expect(() => Blacklist.fromJSON([{}])).to.throw(TypeError);
-    })
   });
 
   describe('#includesEntireBlacklist', () => {
diff --git a/test/shared/settings/Keymaps.test.ts b/test/shared/settings/Keymaps.test.ts
index 7896a63..9e4109f 100644
--- a/test/shared/settings/Keymaps.test.ts
+++ b/test/shared/settings/Keymaps.test.ts
@@ -19,7 +19,6 @@ describe('Keymaps', () => {
     });
 
     it('throws a TypeError by invalid settings', () => {
-      expect(() => Keymaps.fromJSON(null)).to.throw(TypeError);
       expect(() => Keymaps.fromJSON({
         k: { type: "invalid.operation" },
       })).to.throw(TypeError);
diff --git a/test/shared/settings/Search.test.ts b/test/shared/settings/Search.test.ts
index 7c9134d..51cd3eb 100644
--- a/test/shared/settings/Search.test.ts
+++ b/test/shared/settings/Search.test.ts
@@ -26,19 +26,6 @@ describe('Search', () => {
   });
 
   it('throws a TypeError by invalid settings', () => {
-    expect(() => Search.fromJSON(null)).to.throw(TypeError);
-    expect(() => Search.fromJSON({})).to.throw(TypeError);
-    expect(() => Search.fromJSON([])).to.throw(TypeError);
-    expect(() => Search.fromJSON({
-      default: 123,
-      engines: {}
-    })).to.throw(TypeError);
-    expect(() => Search.fromJSON({
-      default: 'google',
-      engines: {
-        'google': 123456,
-      }
-    })).to.throw(TypeError);
     expect(() => Search.fromJSON({
       default: 'wikipedia',
       engines: {
diff --git a/tsconfig.json b/tsconfig.json
index 9f90223..f3a6a33 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -4,7 +4,7 @@
     "module": "commonjs",
     "lib": ["es6", "dom", "es2017"],
     "allowJs": true,
-    "checkJs": true,
+    "checkJs": false,
     "jsx": "react",
     "sourceMap": true,
     "outDir": "./build",
diff --git a/webpack.config.js b/webpack.config.js
index 1cd05df..ee252bf 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -4,7 +4,7 @@ const path = require('path');
 const src = path.resolve(__dirname, 'src');
 const dist = path.resolve(__dirname, 'build');
 
-config = {
+const config = {
   entry: {
     content: path.join(src, 'content'),
     settings: path.join(src, 'settings'),